Single sign-on (SSO) to web services (e.g., web sites, web applications, etc.) is currently available and is increasingly being adopted. By way of example, in conventional systems, an SSO service proxies web sites that require a sign-on by a user, e.g., a log-in page that secures access to additional, authenticated post log-in pages. When a user authenticates to the SSO service and requests a web site, the SSO service provides the user's log-in credentials/authentication data to the flow, as the SSO service has previously stored the necessary data for doing so. This provides a single sign-on capability, i.e., the user need only authenticate to the SSO service, which handles remaining log-ins for the web services. The user may configure the SSO service, e.g., give it user access credentials for various web services.